600 watt? Then you need a capacitor of 250V or higher, but forget about that for now. The thing with compression drivers is that they are very loud in the area 1 kHz to 10 KHz, a tall bulge. A capacitor is needed to kill the rise, from high to low frequency. The shape of the bulge is probably the same with the new driver, only it is taller, louder, around 5 kHz. You need to attenuate more through add-on resistors. That's good news, because it will alleviate the heat of the originals. I think 10 ohm more on each 33 ohm resistor will be just fine. Solder free one end of each resistor and insert the 10 ohm in series, to make 43 ohm on both. 10 watt each should do for the news ones. If this is too quiet for you, put an extra 10 ohm in parallel with each 10 ohm, and you should be where you want the sound to be. No need to worry about the capacitor, if you ask me. Keep it where it is.
Here's a shot from the spec sheet of a compression driver I use.
Attachments
BMS are some seriously nice drivers, german engineering at its finest 😀
The current capacitors are 250v, but I have access to Turbosound 250/400v so will be able to fit them with some quality parts 🙂
The current capacitors are 250v, but I have access to Turbosound 250/400v so will be able to fit them with some quality parts 🙂
If the horn is too loud mainly in the upper end, a smaller uF value on the capacitor is the way to go, giving more resistance to the horn in the upper end. Maybe 0.47 uF will sound good and level. No need to change the resistors then.
Like AllenB said, you probably need to do both. 113 dB down to 97 dB is a big difference. I'd try a swap for 0.47 uF and 10 ohm more on each 33 ohm. From there you can tweak it.
Like AllenB said, you probably need to do both. 113 dB down to 97 dB is a big difference. I'd try a swap for 0.47 uF and 10 ohm more on each 33 ohm. From there you can tweak it.
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Great 🙂
Bit of a silly question now - the current capacitors are marked in Joules and the one's I'm buying are in Farads.
When I use the equation C = q / V I have the value of 60mF for the bass. This is massive!! In one forum they simply switched between the two units - is this acceptable?
Thanks again!
Bit of a silly question now - the current capacitors are marked in Joules and the one's I'm buying are in Farads.
When I use the equation C = q / V I have the value of 60mF for the bass. This is massive!! In one forum they simply switched between the two units - is this acceptable?
Thanks again!
Sorry but the "J" doesn't mean Joules. No capacitors are marked in Joules, ever (as far as I know). The J is a tolerance code.
Getting there!
Decided on the resistor value, and am down to fractions of a uF for the capacitor - this CD really doesn't need much VHF boost. Becomes very fatiguing and sibiliant quite quickly.
I will post final values and findings soon, in the meantime, heres a pic (because everyone loves photos!).
Below is DEQ2496, DCX2496, Void QX5, Turbo horn with BMS4544-8, DBX mic, 6u shockmount sleeve, and Punishers in back. Apologies for poor focusing 😀
Decided on the resistor value, and am down to fractions of a uF for the capacitor - this CD really doesn't need much VHF boost. Becomes very fatiguing and sibiliant quite quickly.
I will post final values and findings soon, in the meantime, heres a pic (because everyone loves photos!).
Below is DEQ2496, DCX2496, Void QX5, Turbo horn with BMS4544-8, DBX mic, 6u shockmount sleeve, and Punishers in back. Apologies for poor focusing 😀
An externally hosted image should be here but it was not working when we last tested it.
Okay, now the CD has settled in , no need for any extra VHF - sounds beautiful as is 
Just wish I had a larger horn to support lower 😀
Final values are:
2 * 10uF (Turbosound 400v) on bass - parallel to give 20uF, 12dB/oct
4 * 2.2uF (Ansar 450v) on treble - paralleled up again to 2 *4.4uF, 24dB/oct
Lpad = 24R, up from 17.5R.
Xover = 1380Hz (measured) down from 1800Hz approx.
Just wish I had a larger horn to support lower 😀
Final values are:
2 * 10uF (Turbosound 400v) on bass - parallel to give 20uF, 12dB/oct
4 * 2.2uF (Ansar 450v) on treble - paralleled up again to 2 *4.4uF, 24dB/oct
Lpad = 24R, up from 17.5R.
Xover = 1380Hz (measured) down from 1800Hz approx.
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